Predicting effects of wettability variations on displacement behavior and their incorporation into inflow performance

Abstract

Wettability plays a crucial role in reservoir fluid dynamics. Wettability controls the initial fluid distribution, fluid movement, further displacement of one fluid by another and hence effecting recovery from a reservoir. Wettability also has strong influence on capillary pressure and relative permeability. During different stages of reservoir development and depletion, this phenomenon becomes further complex, when wettability changes with the passage of time as a result of undergoing several processes. To-date, correlations are available for re-generating the laboratory data for capillary pressure curves, but there is still an immense need of set of correlations which can predict the capillary pressure curve behavior at any prevailing wettability conditions, when its behavior at any wettability is known. Keeping it in view, effective saturation correlation is modified and a set of correlations have been developed which can generate capillary pressure data at any prevailing wettability condition. Furthermore, the methodology for generating the corresponding relative permeability data at any wettability condition has been formulated. In order to use it in a time efficient manner, state-of-the-art system, comprising of suite of softwares have been designed, which is capable of generating capillary pressure and relative permeability curves, efficiently. In addition, the developed system is also capable of performing tubing flow calculations, providing real time monitoring and analyzing of subsurface production systems. The developed set of correlations and the suite of softwares, in conjunction with reservoir simulator, Eclipse 100, collectively named as state-of-the-art Subsurface Flow System Optimizer and Designer have been used for simulation studies of conventional and naturally fractured reservoir. The obtained results show improved history match and hence resulting into improved forecast and decision making, as a result of better understanding of wettability variations effect on displacement behavior and their incorporation into Subsurface Flow System Optimizer and Designer.